Minds are in limited supply, and each mind has a limited capacity for memes, and hence there is considerable competition among memes for entry in as many minds as possible.

The evidence for evolution pours in, not only from geology, paleontology, biogeography, and anatomy, but of course from molecular biology and every other branch of the life sciences.

In 50 years - or 20 years, or 200 years - our current epistemic horizon (the Big Bang, roughly) may look as parochial as the horizon Newton had to settle for in his day, but no doubt there will still be good questions whose answers elude us.

As every scuba diver knows, panic is your worst enemy: when it hits, your mind starts to thrash and you are likely to do something really stupid and self-destructive.

There may be things that are completely unknowable to us, so we must be careful not to treat the limits of our knowledge as sure guides to the limit of what there is.

Some philosophers can't bear to say simple things, like "Suppose a dog bites a man." They feel obliged instead to say, "Suppose a dog d bites a man m at time t," thereby demonstrating their unshakable commitment to logical rigor, even though they don't go on to manipulate any formulae involving d, m, and t.

Some cultural phenomena bear a striking resemblance to the cells of cell biology, actively preserving themselves in their social environments, finding the nutrients they need and fending off the causes of their dissolution.